Aerodynamic recirculating bulk material separator

Abstract

An aerodynamic recirculating separator of bulk materials that includes an air blower capable of forming an air stream, an outlet stream directing means, a separation chamber including two inlets and two outlets, a loading hopper, at least one discharge channel, a return air duct including a plurality of turning portions, and at least one residue collection chamber. An outlet of the air blower connects to the first inlet of the separation chamber, an outlet of the loading hopper connects to the second inlet of the separation chamber, the first outlet of the separation chamber connects to the return air duct, and the second outlet of the separation chamber connects to the at least one discharge channel. The air blower, the separation chamber, and the return air duct are consecutively connected so as to form a recirculation channel. The separator forms a material particle flow from the loading hopper to the separation chamber, to distribute commercial particles by their aerodynamic parameters in the separation chamber as the commercial particles fall from the loading hopper and are blown by the air stream formed by the air blower, and to remove the commercial particles through the at least one discharge channel. The separator forces remaining material particles into the at least one horizontally flared portion, directs at least a part of the remaining material particles into a residue collection chamber by way of gravity, and injects air into the separation chamber via the discharge channels. The first downstream horizontally flared portion includes a downwardly curved bottom wall and an opening in communication with said flared portion and the external environment. The opening is disposed in a smooth turn zone from said flared portion to the first of the plurality of turning portions, which has an upward turn.

The invention claimed is: 
     
       1. An aerodynamic recirculating separator of bulk materials, comprising:
 an air blower capable of forming an air stream and including an outlet stream directing means; 
 a separation chamber including a first inlet, a second inlet, a first outlet and a second outlet; 
 a loading hopper; 
 at least one discharge channel; 
 a return air duct including a plurality of turning portions; and 
 at least one residue collection chamber; 
 wherein an outlet of the air blower is mated to the first inlet of the separation chamber;
 an outlet of the loading hopper is mated to the second inlet of the separation chamber; 
 the first outlet of the separation chamber is mated to the return air duct; 
 the second outlet of the separation chamber is mated to the at least one discharge channel; 
 the air blower, the separation chamber, and the return air duct are consecutively mated so as to form a recirculation channel; 
 the separator is capable of forming a material particle flow from the loading hopper to the separation chamber, distributing commercial particles by their aerodynamic parameters in the separation chamber as the commercial particles fall from the loading hopper and are blown by the air stream formed by the air blower, and removing the commercial particles through the at least one discharge channel; 
 the return air duct includes at least one horizontally flared portion, in communication with at least one residue collection chamber via an opening in a bottom wall of the return air duct; 
 the separator is capable of forcing remaining material particles into the horizontally flared portion and directing at least a part of the remaining material particles into the at least one residue collection chamber by way of gravity; 
 wherein the separator is capable of injecting air into the separation chamber via the at least one discharge channel;
 the first downstream horizontally flared portion includes a downwardly curved bottom wall between the beginning of the first downstream horizontally flared portion and the opening of the first downstream horizontally flared portion; 
 the opening of the first downstream horizontally flared portion is disposed in a smooth turn zone from the first downstream horizontally flared portion to the first of the plurality of turning portions, the first of the plurality of turning portions having an upward turn; and 
 the opening of the first downstream horizontally flared portion is the only opening of the return air duct that is in permanent communication with the external environment. 
 
 
 
     
     
       2. The separator of  claim 1 , wherein the outlet stream directing means is capable of setting a direction having a component directed away from the at least one discharge channel. 
     
     
       3. The separator of  claim 1 , wherein the outlet stream directing means comprises a louver screen. 
     
     
       4. The separator of  claim 1 , wherein the opening of the first downstream horizontally flared portion is covered by a plurality of vanes directed opposite to the air stream. 
     
     
       5. The separator of  claim 1 , further comprising:
 at least two residue collection chambers; and 
 at least two horizontally flared portions; 
 wherein a second downstream residue collection chamber lies in the zone of a second downstream horizontally flared portion; and 
 the residue collection chambers, with the exception of the first of the at least two residue collection chambers, include a dumping means adapted for temporary opening. 
 
     
     
       6. The separator of  claim 5 , wherein the dumping means comprises valves capable of opening under the effect of the weight of the bulk material accumulated in the corresponding residue collection chamber. 
     
     
       7. The separator of  claim 1 , further comprising:
 a top air splitter, the top air splitter being disposed at the inlet part of the first downstream horizontally flared portion, at the opposite side from the first downstream residue collection chamber, the top air splitter being directed co-current with the air stream and capable of deflecting the air stream to the inside zone of the first downstream horizontally flared portion; and 
 a bottom air splitter, the bottom air splitter being disposed at the first of the plurality of turning portions, the first of the plurality of turning portions having an upward turn, the bottom air splitter being disposed at the side of an opening into a subsequent downstream residue collection chamber, the bottom air splitter being directed against the air stream, and capable of retarding the air stream at the zone between the splitter and the surface of the air duct. 
 
     
     
       8. The separator of  claim 1 , wherein the first of the plurality of turning portions is narrowing upwards. 
     
     
       9. The separator of  claim 1 , wherein:
 the at least one discharge channel comprises two pipelines interconnected at their inlets; and 
 the outlets of the pipelines terminate at opposite sides of the separator, and are equipped with gates capable of blocking the outlets. 
 
     
     
       10. The separator of  claim 1 , wherein the residue collection chamber in communication with the opening of the first downstream horizontally flared portion comprises a container disposed under the opening. 
     
     
       11. The separator of  claim 1 , further comprising at least two discharge channels. 
     
     
       12. The separator of  claim 11 , wherein a last discharge channel of the at least two discharge channels serves to remove pollutant particles that are lighter than commercial particles. 
     
     
       13. The separator of  claim 11 , wherein a first discharge channel of the at least two discharge channels serves to remove pollutant particles that are heavier than commercial particles. 
     
     
       14. The separator of  claim 1 , further comprising more than three discharge channels. 
     
     
       15. The separator of  claim 1 , wherein the air blower comprises an axial fan. 
     
     
       16. The separator of  claim 1 , wherein a fan rotation frequency controller comprises a frequency converter.